Flame retardant (FR) additives can be used to control or reduce the risk of fire in plastic, i.e., polymer, products. On average, approximately 909,000 tons per year of FR additives are used in the plastic industry alone to make plastic materials less flammable.
Flame retardancy can be achieved by blending polymers with FR additives such as halocarbons (e.g., polybrominated diphenyl ether), phosphorous compounds, organophosphorus compounds, and metal oxides. While small molecule FRs provide a convenient means for reducing the flammability of materials, the small molecule additives can leach out from plastic products during use or after disposal, and can lead to a variety of environmental and health concerns related to contamination and bioaccumulation. With the European Union banning the use of several halogenated FR additives, there remains a need for the development of environmentally friendly, safer, low leaching alternative FR polymers and additives that are suitable for high performance polymers that can be processed at relatively high temperatures. In particular, it would be highly advantageous to develop FR additives that are considered safer and suitable for high performance polymers that are processed at higher temperatures such as polyamides.